128307685 has 16 divisors (see below), whose sum is σ = 175271040. Its totient is φ = 89256640.

The previous prime is 128307679. The next prime is 128307689. The reversal of 128307685 is 586703821.

128307685 = T₄₄₄ + T₄₄₅ + ... + T₉₄₉.

It is not a de Polignac number, because 128307685 - 2⁹ = 128307173 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128307689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49450 + ... + 51979.

It is an arithmetic number, because the mean of its divisors is an integer number (10954440).

Almost surely, 2^128307685 is an apocalyptic number.

It is an amenable number.

128307685 is a deficient number, since it is larger than the sum of its proper divisors (46963355).

128307685 is a wasteful number, since it uses less digits than its factorization.

128307685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101468.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 128307685 is about 11327.2982215531. The cubic root of 128307685 is about 504.3719080889.

The spelling of 128307685 in words is "one hundred twenty-eight million, three hundred seven thousand, six hundred eighty-five".